Abstract
A study has been made of the thermal degradation of polyorganosiloxanes containing various organic radicals, prepared by alcoholysis of acetoxy-derivatives of the corresponding chlorosilanes. The kinetics of thermal degradation of the crosslinked polymers and the composition of the degradation products liberated at various stages up to 900° have been studied by dynamic and isothermal thermogravimetric analysis, and by volumetric gas analysis. It is shown that in thermal degradation of polymethylsiloxanes at 400–480° low-molecular siloxanes are eliminated, of composition identical with that of the original polymer. At higher temperatures all the polyorganosiloxanes studied begin simultaneously to evolve the appropriate hydrocarbon and form polysubstituted derivatives of that hydrocarbon, which form part of the charred residue. Hydrogen is evolved in the last stage of the reaction. An expression is proposed for determining the rate of thermal degradation of polyorganosiloxanes.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call